The present invention relates to an apparatus for inspecting or photographing an eye fundus, and particularly to an optical system whose inspection or photographic picture angle is variable.
When the dimension of the photographic area, for example the picture size of the film of an eye fundus camera, varied, the photographic magnification is varied accordingly. Consequently, a picture with higher magnification is advantageous when a local part must be inspected clearly, while the picture with lower magnification is suitable when a wide area of the eye fundus is to be photographed.
The standard photographic picture angle for an eye fundus camera is 30.degree., while the photographic magnification is about 2.3. The photographic picture angle for the so-called wide angle type eye fundus camera is 45.degree., while the photographic magnification is about 1.8. Consequently, the picture angle of 30.degree. is suitable when a small area is to be inspected in detail, while the 45.degree. angle or more is suitable when a large area is to be inspected so as to confirm a symptom, for example, during an overall inspection.